Monosynaptic tracing maps brain-wide afferent oligodendrocyte precursor cell connectivity.

Area of Science:

• Neuroscience
• Cell Biology
• Synaptic Plasticity

Background:

• Neurons form synapses with oligodendrocyte precursor cells (OPCs), but the specific circuit context is not well understood.
• Understanding these interactions is crucial for comprehending glial cell function in neural circuits.

Purpose of the Study:

• To investigate the sources and extent of synaptic inputs onto OPCs in adult mice.
• To characterize the nature (excitatory/inhibitory) and stability of these neuron-OPC synapses.

Main Methods:

• Utilized monosynaptically-restricted rabies virus tracing to identify afferent synaptic inputs to OPCs.
• Focused tracing efforts in secondary motor cortex, corpus callosum, and primary somatosensory cortex.
• Quantified synaptic inputs and assessed stability under sensory deprivation (whisker trimming).

Main Results:

• Identified extensive synaptic inputs to OPCs from functionally interconnected cortical areas and thalamic nuclei.
• Demonstrated that OPCs have broad synaptic access to brain-wide projection networks.
• Found consistent numbers of excitatory and inhibitory inputs across brain regions, with stability in barrel cortex despite sensory changes.

Conclusions:

• OPCs receive comprehensive synaptic input from diverse, functionally related brain regions.
• Neuron-OPC synaptic connections are widespread and robust, suggesting a significant role in neural circuit regulation.
• These inputs remain stable, indicating resilience to changes in sensory experience.